Organic light-emitting device

ABSTRACT

An organic light-emitting device includes an auxiliary layer located between a first electrode and a hole injection layer or a hole transport layer and including a metal fluoride. The metal of the metal fluoride may be a Group III metal having a high work function of 3.8 eV or more. The hole injection barrier at the interface between the first electrode and the hole injection layer may be adjusted by the fluoride of the high work function metal in the auxiliary layer so that the electron-hole charge balance and the efficiency of the organic light-emitting device may be improved.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0023845, filed on Feb. 26, 2020, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND 1. Field

One or more aspects of embodiments of the present disclosure relate to an organic light-emitting device.

2. Description of Related Art

Organic light-emitting devices are self-emission devices that produce full-color images, and may also have wide viewing angles, high contrast ratios, short response times, and/or excellent characteristics in terms of brightness, driving voltage, and/or response speed, compared to devices in the art.

One example of an organic light-emitting device includes a first electrode disposed on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially disposed on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers (such as holes and electrons) may recombine in the emission layer to produce excitons. These excitons may transition from an excited state to a ground state to thereby generate light.

SUMMARY

One or more aspects of embodiments of the present disclosure are directed toward an organic light-emitting device including an auxiliary layer, the auxiliary layer being located between a first electrode and one of a hole injection layer or a hole transport layer, and including a fluoride of a metal satisfying a set or predetermined condition.

Additional aspects will be set forth in part in the description that follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

One or more example embodiments of the present disclosure provide an organic light-emitting device including a first electrode;

-   -   a second electrode facing the first electrode; and     -   an organic layer including: an emission layer between the first         electrode and the second electrode, and a hole transport region         between the first electrode and the emission layer,     -   wherein the hole transport region includes a hole injection         layer and/or a hole transport layer located between the first         electrode and the emission layer, and an auxiliary layer between         the first electrode and one of the hole injection layer or the         hole transport layer,     -   wherein the auxiliary layer includes a fluoride of a metal         having a work function of 3.8 eV or more, and     -   the one of the hole injection layer or the hole transport layer         includes a p-dopant.

In one embodiment, the metal having a work function of 3.8 eV or more may be a Group III metal.

In one embodiment, the metal having a work function of 3.8 eV or more may be at least one selected from aluminum (Al), gallium (Ga), indium (In), and thallium (Tl).

In one embodiment, the auxiliary layer may include at least one selected from AlF₃, GaF₃, InF₃, and TlF₃.

In one embodiment, the auxiliary layer may include (e.g., consist of) the fluoride of the metal and may have a single-film form (e.g., may include a single film of the fluoride of the metal and), or may further include a hole transport material.

In one embodiment, the auxiliary layer may further include a hole transport material, and

-   -   may include the fluoride of the metal and the hole transport         material at a volume ratio of 100:x (here, x is greater than 0         and less than 100).

In some embodiments, the hole transport material may be at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, spiro-TPD, spiro-NPB, α-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sulfonate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

-   -   L₂₀₁ to L₂₀₅ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   xa1 to xa4 may each independently be selected from 0, 1, 2, and         3,     -   xa5 may be selected from 1, 2, 3, 4, and 5, and     -   R₂₀₁ to R₂₀₄ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group.

In one embodiment, the auxiliary layer may be in direct contact with the first electrode.

In one embodiment, the auxiliary layer may be in direct contact with the one of the hole injection layer or the hole transport layer.

In one embodiment, the auxiliary layer may have a thickness of about 5 Å to about 200 Å.

In one embodiment, the p-dopant may have a lowest unoccupied molecular orbital (LUMO) energy level of less than about −3.5 eV.

In one embodiment, the p-dopant may include at least one selected from quinone derivatives, metal oxides, cyano group-containing compounds, and alkyl halides.

In one embodiment, the p-dopant may be a metal oxide, and may be generated according to Reaction Scheme 1 at an interface between the auxiliary layer and the one of the hole injection layer or the hole transport layer, and may include a compound represented by metal M and M′F₃: 3MF_(α)+αM′→3M+αM′F₃.  Reaction Scheme 1

In Reaction Scheme 1, M is a Group III metal, M′ is a metal element included in the metal oxide included in the one of the hole injection layer or the hole transport layer, and a satisfies 0<α<5.

In one embodiment, the one of the hole injection layer or the hole transport layer may further include a material including an electron withdrawing group (EWG).

In one embodiment, the hole transport region may include: the hole injection layer; and the hole transport layer between the hole injection layer and the emission layer, the hole injection layer may include a p-dopant, and the hole transport layer may include a hole transport material.

In one embodiment, the hole transport region may further include an electron blocking layer between the hole transport layer and the emission layer.

In one embodiment, an electron transport region may be included between the emission layer and the second electrode, and the electron transport region may include an electron transport material.

In one embodiment, the electron transport region may include at least one layer selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer.

One or more example embodiments of the present disclosure provide an organic light-emitting device including a first electrode,

-   -   a second electrode facing the first electrode,     -   m emission units between the first electrode and the second         electrode, and     -   m−1 charge generating layers between two adjacent emission units         of the m emission units, each of the charge generating layers         including one n-type charge generating layer and one p-type         charge generating layer,     -   wherein m is an integer of 2 or more,     -   wherein the m emission units each include a hole transport         region, an emission unit, and an electron transport region,         which are arranged in order,     -   wherein a first hole transport region among the m hole transport         regions includes a hole injection layer, a hole transport layer,         or a combination thereof, each located between the first         electrode and a first emission layer, and an auxiliary layer         between the first electrode and one of the hole injection layer         or the hole transport layer,     -   wherein the auxiliary layer includes a fluoride of a metal         having a work function of 3.8 eV or more, and     -   the one of the hole injection layer or the hole transport layer         includes a p-dopant.

One or more example embodiments of the present disclosure provide a display apparatus including a thin-film transistor including a source electrode, a drain electrode, an activation layer, and the organic light-emitting device, wherein the first electrode of the organic light-emitting device is in electrical connection with one of the source electrode or the drain electrode of the thin-film transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic view of a structure of an organic light-emitting device according to an embodiment; and

FIG. 2 is a schematic view of a structure of an organic light-emitting device according to another embodiment.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout, and duplicative descriptions thereof may not be provided. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the drawings, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b, or c” may indicate only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Expressions such as “at least one of,” “one of,” and “selected from,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

It will be further understood that the terms “includes,” “including,” “comprises,” and/or “comprising,” used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure”.

It will be understood that when a layer, region, or component is referred to as being “on” or “onto” another layer, region, or component, it may be directly or indirectly formed on the other layer, region, or component. In some embodiments, for example, intervening layers, regions, or components may be present. When an element is referred to as being “directly on,” “[in] direct contact,” “directly connected to,” or “directly coupled to” another element, there are no intervening elements present.

Sizes and dimensions of elements in the drawings may be exaggerated for convenience of explanation. In other words, because the sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments of the present disclosure are not limited thereto.

The term “organic layer” as used herein refers to a single layer and/or a plurality of layers disposed between the first electrode and the second electrode of an organic light-emitting device. Materials included in the “organic layer” are not limited to being organic materials.

The expression “(an organic layer) includes a compound represented by Formula 1” as used herein may include a case in which “(an organic layer) includes one compound of Formula 1” and a case in which “(an organic layer) includes two or more different compounds of Formula 1”.

Hereinafter, embodiments of the present disclosure will be described in more detail with reference to the attached drawings.

Description of FIG. 1

FIG. 1 is a schematic cross-sectional view of an organic light-emitting device 10 according to an embodiment of the present disclosure. The organic light-emitting device 10 includes a first electrode 110, an emission layer 150, and a second electrode 190.

Referring to FIG. 1 , the organic light-emitting device 10 includes: a first electrode 110; a second electrode 190 facing the first electrode 110; an organic layer including an emission layer 150 between the first electrode 110 and the second electrode 190; and a hole transport region 130 between the first electrode 110 and the emission layer 150, wherein the hole transport region 130 includes a hole injection layer 132 between the first electrode 110 and the emission layer 150 and an auxiliary layer 131 between the first electrode 110 and the hole injection layer 132, the auxiliary layer 131 includes a fluoride of a metal having a work function of 3.8 eV or more (e.g., a metal fluoride), and the hole injection layer 132 includes a p-dopant.

Here, the work function may be measured by using a surface analyzer model AC2, which is a photoelectron spectrometer in air (PESA) manufactured by RIKEN KEIKI, Co. Ltd., but embodiments of the present disclosure are not limited thereto.

In some embodiments, the metal may have a work function of 7.0 eV or less.

In some embodiments, the metal having a work function of 3.8 eV or more may be a Group III metal.

In the related art, a high dielectric constant material has been applied to an organic light-emitting device to reinforce a carrier tunneling effect, but a reduction in driving voltage could not be achieved, and hole injection (hole injection characteristics) was poor.

The organic light-emitting device 10 according to an embodiment of the present disclosure includes an auxiliary layer 131 that is located between the first electrode 110 and the hole injection layer 132, and includes a metal having a high work function of 3.8 eV or more, for example, a Group III metal. Because the metal has a high work function and electric field-induced band bending (tunneling effect) is reinforced, an injection barrier at an interface between the first electrode 110 and the hole injection layer 132 may be lowered, and hole injection (hole injection characteristics) of the organic light-emitting device 10 may be improved.

For example, because the metal fluoride included in the auxiliary layer 131 is limited to including a Group III metal, improved electron-hole charge balance in the organic light-emitting device 10 due to adjustment of the hole injection barrier by the high-work-function metal may result in improved luminescence efficiency of the device.

In addition, because the hole injection layer 132 or the hole transport layer includes a p-dopant, the hole injection barrier may be adjusted by substituting the high-work-function metal of the fluoride through reaction of the fluoride with a metal element included in the p-dopant.

The auxiliary layer 131 may function as a dielectric layer.

The metal having a work function of 3.8 eV or more is not particularly limited, but may be a Group III metal as described above, and for example, may be at least one selected from aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). For example, the work function of Al may be from about 4.06 eV to about 4.26 eV, the work function of Ga may be about 4.32 eV, the work function of In may be about 4.09 eV, and the work function of Tl may be about 3.84 eV.

In some embodiments, the auxiliary layer 131 may include at least one selected from AlF₃, GaF₃, InF₃, and TlF₃.

The auxiliary layer 131 may include (e.g., consist of) the fluoride of the metal and may be a single-film (e.g., a film including or formed of a single material), or may further include a hole transport material.

For example, the auxiliary layer 131 may further include a hole transport material, and may include the fluoride of a metal and the hole transport material at a volume ratio of 100:x (here, x is greater than 0 and less than 100). For example, an amount of the fluoride of a metal included in the auxiliary layer 131 is greater than an amount of the hole transport material.

The hole transport material will be described in further detail below.

In one embodiment, the auxiliary layer 131 may be in direct contact with the first electrode 110.

In one embodiment, the auxiliary layer 131 may be in direct contact with the hole injection layer 132.

For example, the auxiliary layer 131 may be present at an interface between the first electrode 110 and the hole injection layer 132. For example, the auxiliary layer 131 may be directly between the first electrode 110 and the hole injection layer 132 (e.g., with no intervening layers).

In one embodiment, the auxiliary layer 131 may have a thickness of about 5 Å to about 200 Å.

When the thickness of the auxiliary layer 131 satisfies the range, a hole injection characteristic may vary due to tunneling/thermionic emission according to a film thickness of a fluoride (e.g., hole injection may occur via tunneling and/or thermionic emission, as controlled by the thickness of the metal fluoride film), an optimal or suitable electron-hole charge balance may be achieved, and the efficiency of an organic light-emitting device may be improved.

In one embodiment, a LUMO energy level of a p-dopant included in the hole injection layer 132 may be less than about −3.5 eV.

For example, the p-dopant may include at least one selected from quinone derivatives, metal oxides, cyano group-containing compounds, and alkyl halides. The p-dopant will be described in more detail below.

For example, the p-dopant may be a metal oxide and may be generated according to Reaction Scheme 1 at an interface between the auxiliary layer 131 and the hole injection layer 132, and may include a compound represented by metal M and M′F₃: 3MF_(α)+αM′→3M+αM′F₃.  Reaction Scheme 1

In Reaction Scheme 1, M is a Group III metal, M′ is a metal element included in the metal oxide (p-dopant) included in the hole injection layer, and a satisfies 0<α<5.

Due to the substitution reaction of the Group III metal and M′ (e.g., as shown in Reaction Scheme 1), a hole injection characteristic of a device may be improved.

In one embodiment, the hole injection layer 132 may further include a material including an electron withdrawing group (EWG).

The EWG is not particularly limited, but may be, for example, a cyanide group (—CN and —NC), a hydroxyl group (—OH), a halide group (—F, —Cl, —Br, and —I), a π-electron-deficient nitrogen-containing ring, or any combination thereof.

In one embodiment, the hole transport region 130 may further include a hole transport layer 133 between the hole injection layer 132 and the emission layer 150, and the hole transport layer 133 may include a hole transport material.

The hole transport material may be understood by referring to the related description below.

For example, the hole injection layer 132 and the hole transport layer 133 may be different (e.g., different in composition, material, and/or structure) from each other.

For example, the hole transport region 130 may further include an electron blocking layer between the hole transport layer 133 and the emission layer 150.

Hereinafter, each component of an organic light-emitting device of the present disclosure will be described in more detail with reference to FIG. 1 .

First Electrode 110

In FIG. 1 , a substrate may be disposed under the first electrode 110 and/or above the second electrode 190. The substrate may be a glass substrate and/or a plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water resistance.

The first electrode 110 may be formed by depositing and/or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, a material for forming the first electrode 110 may be selected from materials with a high work function to facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combination thereof, but embodiments of the present disclosure are not limited thereto. When the first electrode 110 is a semi-transmissive electrode or a reflective electrode, the material for forming the first electrode 110 may be selected from magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and any combination thereof, but embodiments of the present disclosure are not limited thereto.

The first electrode 110 may have a single-layered structure, or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.

Organic Layer

An organic layer may be located on the first electrode 110. The organic layer may include the emission layer 150 and the hole transport region 130 between the emission layer 150 and the first electrode 110.

The organic layer may further include an electron transport region 170 between the second electrode 190 and the emission layer 150.

Hole Transport Region 130 in Organic Layer

The hole transport region 130 may have i) a single-layered structure including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials.

The hole transport region 130 may include at least one layer selected from an electron blocking layer and an emission auxiliary layer, in addition to the auxiliary layer 131, the hole injection layer 132, and the hole transport layer 133.

For example, the hole transport region 130 may have a multi-layered structure having an auxiliary layer 131/hole injection layer 132, an auxiliary layer 131/hole injection layer 132/hole transport layer 133, an auxiliary layer 131/hole injection layer 132/hole transport layer 133/emission auxiliary layer, an auxiliary layer 131/hole injection layer 132/hole transport layer 133/electron blocking layer, or an auxiliary layer 131/hole injection layer 132/hole transport layer 133/emission auxiliary layer, wherein the constituent layers of each structure are sequentially stacked from the first electrode 110 in each stated order, but embodiments of the present disclosure are not limited thereto.

The hole transport region 130 may include a hole transport material.

The hole transport material may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylene dioxythiophene)/poly(4-styrene sulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sulfonate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

-   -   L₂₀₁ to L₂₀₄ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a         substituted or unsubstituted C₁-C₂₀ alkylene group, a         substituted or unsubstituted C₂-C₂₀ alkenylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   xa1 to xa4 may each independently be an integer from 0 to 3,     -   xa5 may be an integer from 1 to 10, and     -   R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group.

For example, in Formula 202, R₂₀₁ and R₂₀₂ may optionally be linked to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be linked to each other via a single bond, a dimethyl-methylene group, or a diphenyl-methylene group.

In one embodiment, in Formulae 201 and 202,

-   -   L₂₀₁ to L₂₀₅ may each independently be selected from:     -   a phenylene group, a pentalenylene group, an indenylene group, a         naphthylene group, an azulenylene group, a heptalenylene group,         an indacenylene group, an acenaphthylene group, a fluorenylene         group, a spiro-bifluorenylene group, a benzofluorenylene group,         a dibenzofluorenylene group, a phenalenylene group, a         phenanthrenylene group, an anthracenylene group, a         fluoranthenylene group, a triphenylenylene group, a pyrenylene         group, a chrysenylene group, a naphthacenylene group, a         picenylene group, a perylenylene group, a pentaphenylene group,         a hexacenylene group, a pentacenylene group, a rubicenylene         group, a coronenylene group, an ovalenylene group, a         thiophenylene group, a furanylene group, a carbazolylene group,         an indolylene group, an isoindolylene group, a benzofuranylene         group, a benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group; and     -   a phenylene group, a pentalenylene group, an indenylene group, a         naphthylene group, an azulenylene group, a heptalenylene group,         an indacenylene group, an acenaphthylene group, a fluorenylene         group, a spiro-bifluorenylene group, a benzofluorenylene group,         a dibenzofluorenylene group, a phenalenylene group, a         phenanthrenylene group, an anthracenylene group, a         fluoranthenylene group, a triphenylenylene group, a pyrenylene         group, a chrysenylene group, a naphthacenylene group, a         picenylene group, a perylenylene group, a pentaphenylene group,         a hexacenylene group, a pentacenylene group, a rubicenylene         group, a coronenylene group, an ovalenylene group, a         thiophenylene group, a furanylene group, a carbazolylene group,         an indolylene group, an isoindolylene group, a benzofuranylene         group, a benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),     -   wherein Q₃₁ to Q₃₃ may each independently be selected from a         C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a         biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from: a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

-   -   a phenyl group, a biphenyl group, a terphenyl group, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group, each substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),     -   wherein Q₃₁ to Q₃₃ may each independently be the same as         described above.

In one or more embodiments, in Formula 201, at least one of R₂₀₁ to R₂₀₃ may each independently be selected from:

-   -   a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl         group, a dibenzofuranyl group, and a dibenzothiophenyl group;         and     -   a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl         group, a dibenzofuranyl group, and a dibenzothiophenyl group,         each substituted with at least one selected from deuterium, —F,         —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an         amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀         alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a         cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a         cyclohexenyl group, a phenyl group, a biphenyl group, a         terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl         group, a phenyl group substituted with —F, a naphthyl group, a         fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group,         a dibenzofuranyl group, and a dibenzothiophenyl group,     -   but embodiments of the present disclosure are not limited         thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may be linked to each other via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be linked to each other via a single bond.

In one or more embodiments, R₂₀₁ to R₂₀₄ in Formula 202 may each independently be selected from:

-   -   a carbazolyl group; and     -   a carbazolyl group substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a         carbazolyl group, a dibenzofuranyl group, and a         dibenzothiophenyl group,     -   but embodiments of the present disclosure are not limited         thereto.

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A:

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A(1), but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A-1, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A:

In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A-1:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

-   -   L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ may each         independently be the same as described above,     -   R₂₁₁ and R₂₁₂ may each independently be the same as described in         connection with R₂₀₃, and     -   R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclopentenyl group, a cyclohexenyl group, a phenyl group, a         biphenyl group, a terphenyl group, a phenyl group substituted         with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a         pentalenyl group, an indenyl group, a naphthyl group, an         azulenyl group, a heptalenyl group, an indacenyl group, an         acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group,         a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl         group, a phenanthrenyl group, an anthracenyl group, a         fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a         chrysenyl group, a naphthacenyl group, a picenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a rubicenyl group, a coronenyl group, an         ovalenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group.

The hole transport region 130 may include at least one compound selected from Compounds HT1 to HT45, but embodiments of the present disclosure are not limited thereto:

A thickness of the hole transport region 130 may be about 105 Å to about 10,000 Å, for example, about 105 Å to about 1,000 Å. A thickness of the hole injection layer 132 may be about 50 Å to about 9,000 Å, for example, about 50 Å to about 1,000 Å, and when the hole transport region 130 includes the hole transport layer 133, a thickness of the hole transport layer 133 may be about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When thicknesses of the hole transport region 130, hole injection layer 132, and hole transport layer 133 satisfy these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase the light-emission efficiency of the device by compensating for an optical resonance distance of light emitted by the emission layer 150, and the electron blocking layer may block or reduce the flow of electrons from the electron transport layer 170. The emission auxiliary layer and the electron blocking layer may each independently include the same materials described above.

p-Dopant

The hole injection layer 132 included in the hole transport region 130 may include, as described above, a p-dopant.

In addition, the hole transport region 130 may further include, in addition to these materials, a charge-generation material for improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region 130.

The charge-generation material may be, for example, a p-dopant.

In one embodiment, a LUMO energy level of the p-dopant may be less than −3.5 eV.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, a cyano group-containing compound, a transition metal halide, and a transition metal telluride, but embodiments of the present disclosure are not limited thereto.

The term “transition metal” includes d-block elements of the Periodic Table of Elements, for example, elements in Group 3 to Group 12. For example, the transition metal may denote elements of Period 4 to Period 7.

For example, the transition metal halide may be at least one selected from CuF, CuCl, CuBr, CuI, NiF₂, NiCl₂, NiBr₂, NiI₂, ZnF₂, ZnCl₂, ZnBr₂, ZnI₂, ZnF₄, and ZnI₄.

For example, the transition metal telluride may be at least one selected from ZnTe, Bi₂Te₃, Bi₇Te₃, Bi₂Te, Bi₄Te₃, BiTe, Bi₆Te₇, Bi₄Te₅, Bi_(x)Te_(y) (0<x<100, 0<y<100, 0<x+y≤100), Sb₂Te₃, In₂Te₃, Ga₂Te₂, Al₂Te₃, Tl₂Te₃, As₂Te₃, GeSbTe, SnTe, PbTe, SiTe, GeTe, FITe, SiGe, AlInSb, AlGaSb, AlAsSb, GaAs, InSb, AlSb, AlAs, Al_(a)In_(a)Sb (0<a<1), Al_(b)In_((1-b))Sb (0<b<1), AlSb, GaSb, and AlInGaAs.

In one embodiment, the p-dopant may include at least one selected from:

-   -   a quinone derivative (such as tetracyanoquinodimethane (TCNQ)         and/or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane         (F4-TCNQ));     -   a metal oxide (such as a tungsten oxide and/or a molybdenum         oxide);     -   1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and     -   a compound represented by Formula 221,     -   but embodiments of the present disclosure are not limited         thereto:

In Formula 221,

-   -   R₂₂₁ to R₂₂₃ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group, and at least one         of R₂₂₁ to R₂₂₃ may have at least one substituent selected from         a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group         substituted with —F, a C₁-C₂₀ alkyl group substituted with —Cl,         a C₁-C₂₀ alkyl group substituted with —Br, and a C₁-C₂₀ alkyl         group substituted with —I.         Emission Layer 150

When the organic light-emitting device 10 is a full-color organic light-emitting device, the emission layer 150 may be patterned into a red emission layer, a green emission layer, and a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer 150 may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers may contact each other or may be separated from each other. In one or more embodiments, the emission layer may include two or more materials selected from a red light-emitting material, a green light-emitting material, and a blue light-emitting material, where the two or more materials may be mixed with each other in a single layer to emit white light.

The emission layer 150 may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant and a fluorescent dopant. The dopant may emit one or more of the first-color light to the third-color light. For example, the first-color light to the third-color light may each independently be selected from blue light, red light, and green light. The amount of the dopant may be about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.

An amount of the dopant in the emission layer 150 may be about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host, but embodiments of the present disclosure are not limited thereto.

A thickness of the emission layer 150 may be about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer 150 is within the range, excellent luminescence characteristics may be obtained without a substantial increase in driving voltage.

Host of Emission Layer 150

In one or more embodiments, the host may include a compound represented by Formula 301: [Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21).  Formula 301

In Formula 301,

-   -   Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic         group or a substituted or unsubstituted C₁-C₆₀ heterocyclic         group,     -   xb11 may be 1, 2, or 3,     -   L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀         cycloalkylene group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀         cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkenylene group, a substituted or unsubstituted         C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀         heteroarylene group, a substituted or unsubstituted divalent         non-aromatic condensed polycyclic group, and a substituted or         unsubstituted divalent non-aromatic condensed heteropolycyclic         group,     -   xb1 may be an integer from 0 to 5,     -   R₃₀₁ may be selected from deuterium, —F, —Cl, —Br, —I, a         hydroxyl group, a cyano group, a nitro group, an amidino group,         a hydrazino group, a hydrazono group, a substituted or         unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted         C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀         alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy         group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, a substituted or unsubstituted monovalent non-aromatic         condensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃),         —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and         —P(═O)(Q₃₀₁)(Q₃₀₂), and     -   xb21 may be an integer from 1 to 5,     -   wherein Q₃₀₁ to Q₃₀₃ may each independently be selected from a         C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a         biphenyl group, a terphenyl group, and a naphthyl group, but         embodiments of the present disclosure are not limited thereto.

In one embodiment, Ar₃₀₁ in Formula 301 may be selected from:

-   -   a naphthalene group, a fluorene group, a spiro-bifluorene group,         a benzofluorene group, a dibenzofluorene group, a phenalene         group, a phenanthrene group, an anthracene group, a fluoranthene         group, a triphenylene group, a pyrene group, a chrysene group, a         naphthacene group, a picene group, a perylene group, a         pentaphene group, an indenoanthracene group, a dibenzofuran         group, and a dibenzothiophene group; and     -   a naphthalene group, a fluorene group, a spiro-bifluorene group,         a benzofluorene group, a dibenzofluorene group, a phenalene         group, a phenanthrene group, an anthracene group, a fluoranthene         group, a triphenylene group, a pyrene group, a chrysene group, a         naphthacene group, a picene group, a perylene group, a         pentaphene group, an indenoanthracene group, a dibenzofuran         group, and a dibenzothiophene group, each substituted with at         least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl         group, a cyano group, a nitro group, an amidino group, a         hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a         C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃),         —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and         —P(═O)(Q₃₁)(Q₃₂),     -   wherein Q₃₁ to Q₃₃ may each independently be selected from a         C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a         biphenyl group, a terphenyl group, and a naphthyl group, but         embodiments of the present disclosure are not limited thereto.

When xb11 in Formula 301 is 2 or more, two or more Ar₃₀₁(s) may be linked via a single bond.

In one or more embodiments, the compound represented by Formula 301 may be represented by Formula 301-1 or 301-2:

In Formulae 301-1 and 301-2

-   -   A₃₀₁ to A₃₀₄ may each independently be selected from a benzene         ring, a naphthalene ring, a phenanthrene ring, a fluoranthene         ring, a triphenylene ring, a pyrene ring, a chrysene ring, a         pyridine ring, a pyrimidine ring, an indene ring, a fluorene         ring, a spiro-bifluorene ring, a benzofluorene ring, a         dibenzofluorene ring, an indole ring, a carbazole ring, a         benzocarbazole ring, a dibenzocarbazole ring, a furan ring, a         benzofuran ring, a dibenzofuran ring, a naphthofuran ring, a         benzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring,         a benzothiophene ring, a dibenzothiophene ring, a         naphthothiophene ring, a benzonaphthothiophene ring, and a         dinaphthothiophene ring,     -   X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],     -   R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl         group, a biphenyl group, a terphenyl group, a naphthyl group         —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),         —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),     -   xb22 and xb23 may each independently be 0, 1, or 2,     -   L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ may each independently be the         same as described above,     -   L₃₀₂ to L₃₀₄ may each independently be the same as described in         connection with L₃₀₁,     -   xb2 to xb4 may each independently be the same as described in         connection with xb1, and     -   R₃₀₂ to R₃₀₄ may each independently be the same as described in         connection with R₃₀₁.

For example, L₃₀₁ to L₃₀₄ in Formulae 301, 301-1, and 301-2 may each independently be selected from:

-   -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group; and     -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a nitro group, an amidino group, a hydrazino group,         a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,         a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, an         azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),         —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),     -   wherein Q₃₁ to Q₃₃ may each independently be the same as         described above.

In one embodiment, R₃₀₁ to R₃₀₄ in Formulae 301, 301-1, and 301-2 may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group; and     -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, an         azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),         —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),     -   wherein Q₃₁ to Q₃₃ may each independently be the same as         described above.

In one or more embodiments, the host may include an alkaline earth metal complex. For example, the host may be selected from a Be complex (for example, Compound H55) and an Mg complex. In some embodiments, the host may be a Zn complex.

The host may include at least one selected from 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and at least one selected from Compounds H1 to H55, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the host may include at least one of a silicon-containing compound (for example, BCPDS) and a phosphine oxide-containing compound (for example, POPCPA).

The host may include only one compound, or may include two or more compounds that are different from each other. In one or more embodiments, the host may have other suitable modifications.

Fluorescent Dopant in Emission Layer 150

The fluorescent dopant may further include an arylamine compound or a styrylamine compound.

The fluorescent dopant may include a compound represented by Formula 501:

In Formula 501,

-   -   Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic         group or a substituted or unsubstituted C₁-C₆₀ heterocyclic         group,     -   L₅₀₁ to L₅₀₃ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group,         a substituted or unsubstituted C₆-C₆₀ arylene group, a         substituted or unsubstituted C₁-C₆₀ heteroarylene group, a         substituted or unsubstituted divalent non-aromatic condensed         polycyclic group, and a substituted or unsubstituted divalent         non-aromatic condensed heteropolycyclic group,     -   xd1 to xd3 may each independently be an integer from 0 to 3,     -   R₅₀₁ and R₅₀₂ may each independently be selected from a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, and a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group, and     -   xd4 may be an integer from 1 to 6.

In one embodiment, Ar₅₀₁ in Formula 501 may be selected from:

-   -   a naphthalene group, a heptalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group,         and an indenophenanthrene group; and     -   a naphthalene group, a heptalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group,         and an indenophenanthrene group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy         group, a phenyl group, a biphenyl group, a terphenyl group, and         a naphthyl group.

In one or more embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may each independently be selected from:

-   -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group; and     -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, and a         pyridinylene group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group.

In one or more embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group; and     -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl         group, each substituted with at least one selected from         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl         group, a biphenyl group, a terphenyl group, a naphthyl group, a         fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl         group, a dibenzofluorenyl group, a phenanthrenyl group, an         anthracenyl group, a fluoranthenyl group, a triphenylenyl group,         a pyrenyl group, a chrysenyl group, a perylenyl group, a         pentaphenyl group, a hexacenyl group, a pentacenyl group, a         thiophenyl group, a furanyl group, a carbazolyl group, an         indolyl group, an isoindolyl group, a benzofuranyl group, a         benzothiophenyl group, a dibenzofuranyl group, a         dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),     -   wherein Q₃₁ to Q₃₃ may be selected from a C₁-C₁₀ alkyl group, a         C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a         terphenyl group, and a naphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodiments of the present disclosure are not limited thereto.

For example, the fluorescent dopant may be selected from Compounds FD1 to FD23:

In one or more embodiments, the fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto:

Electron Transport Region 170 in Organic Layer

The electron transport region 170 may have i) a single-layered structure including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials.

The electron transport region 170 may include at least one layer selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer, but embodiments of the present disclosure are not limited thereto.

For example, the electron transport region 170 may have an electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, a buffer layer/electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, a hole blocking layer/electron control layer/electron transport layer/electron injection layer structure, or a hole blocking layer/buffer layer/electron transport layer/electron injection layer structure, wherein the constituting layers of each structure are sequentially stacked from the emission layer 150, but embodiments of the present disclosure are not limited thereto.

The electron transport region 170 (for example, a buffer layer, a hole blocking layer, an electron control layer, and/or an electron transport layer in the electron transport region 170) may include a metal-free compound containing at least one π-electron-deficient nitrogen-containing ring.

The term “π-electron-deficient nitrogen-containing ring” refers to a C₁-C₆₀ heterocyclic group having at least one *—N═*′ moiety as a ring-forming moiety.

For example, the “π-electron-deficient nitrogen-containing ring” may be: i) a 5-membered to 7-membered heteromonocyclic group having at least one *—N═*′ moiety, ii) a heteropolycyclic group in which two or more 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N═*′ moiety, are condensed with each other, or iii) a heteropolycyclic group in which one or more 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N═*′ moiety, is condensed with at least one C₅-C₆₀ carbocyclic group.

Non-limiting examples of the π-electron-deficient nitrogen-containing ring include an imidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, an indazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a benzoquinoline ring, a phthalazine ring, a naphthyridine ring, a quinoxaline ring, a quinazoline ring, a cinnoline ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a phenazine ring, a benzimidazole ring, an isobenzothiazole ring, a benzoxazole ring, an isobenzoxazole ring, a triazole ring, a tetrazole ring, an oxadiazole ring, a triazine ring, a thiadiazole ring, an imidazopyridine ring, an imidazopyrimidine ring, and an azacarbazole ring.

For example, the electron transport region 170 may include a compound represented by Formula 601: [Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21).  Formula 601

In Formula 601,

-   -   Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic         group or a substituted or unsubstituted C₁-C₆₀ heterocyclic         group,     -   xe11 may be 1, 2, or 3,     -   L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀         cycloalkylene group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀         cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkenylene group, a substituted or unsubstituted         C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀         heteroarylene group, a substituted or unsubstituted divalent         non-aromatic condensed polycyclic group, and a substituted or         unsubstituted divalent non-aromatic condensed heteropolycyclic         group,     -   xe1 may be an integer from 0 to 5,     -   R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀         cycloalkyl group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀         cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀         heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀         aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group,         a substituted or unsubstituted C₆-C₆₀ arylthio group, a         substituted or unsubstituted C₁-C₆₀ heteroaryl group, a         substituted or unsubstituted monovalent non-aromatic condensed         polycyclic group, a substituted or unsubstituted monovalent         non-aromatic condensed heteropolycyclic group,         —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), and         —P(═O)(Q₆₀₁)(Q₆₀₂),     -   Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a         C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a         terphenyl group, or a naphthyl group, and     -   xe21 may be an integer from 1 to 5.

In one embodiment, at least one of the xe11 Ar₆₀₁(s) and the xe21 R₆₀₁(s) may include the π-electron-deficient nitrogen-containing ring.

In one embodiment, ring Ar₆₀₁ in Formula 601 may be selected from:

-   -   a benzene group, a naphthalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group, a         dibenzofuran group, a dibenzothiophene group, a carbazole group,         an imidazole group, a pyrazole group, a thiazole group, an         isothiazole group, an oxazole group, an isoxazole group, a         pyridine group, a pyrazine group, a pyrimidine group, a         pyridazine group, an indazole group, a purine group, a quinoline         group, an isoquinoline group, a benzoquinoline group, a         phthalazine group, a naphthyridine group, a quinoxaline group, a         quinazoline group, a cinnoline group, a phenanthridine group, an         acridine group, a phenanthroline group, a phenazine group, a         benzimidazole group, an isobenzothiazole group, a benzoxazole         group, an isobenzoxazole group, a triazole group, a tetrazole         group, an oxadiazole group, a triazine group, a thiadiazole         group, an imidazopyridine group, an imidazopyrimidine group, and         an azacarbazole group; and     -   a benzene group, a naphthalene group, a fluorene group, a         spiro-bifluorene group, a benzofluorene group, a dibenzofluorene         group, a phenalene group, a phenanthrene group, an anthracene         group, a fluoranthene group, a triphenylene group, a pyrene         group, a chrysene group, a naphthacene group, a picene group, a         perylene group, a pentaphene group, an indenoanthracene group, a         dibenzofuran group, a dibenzothiophene group, a carbazole group,         an imidazole group, a pyrazole group, a thiazole group, an         isothiazole group, an oxazole group, an isoxazole group, a         pyridine group, a pyrazine group, a pyrimidine group, a         pyridazine group, an indazole group, a purine group, a quinoline         group, an isoquinoline group, a benzoquinoline group, a         phthalazine group, a naphthyridine group, a quinoxaline group, a         quinazoline group, a cinnoline group, a phenanthridine group, an         acridine group, a phenanthroline group, a phenazine group, a         benzimidazole group, an isobenzothiazole group, a benzoxazole         group, an isobenzoxazole group, a triazole group, a tetrazole         group, an oxadiazole group, a triazine group, a thiadiazole         group, an imidazopyridine group, an imidazopyrimidine group, and         an azacarbazole group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a nitro group, an amidino group, a hydrazino group,         a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,         a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),     -   wherein Q₃₁ to Q₃₃ may each independently be selected from a         C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a         biphenyl group, a terphenyl group, and a naphthyl group.

When xe11 in Formula 601 is 2 or more, two or more Ar₆₀₁(s) may be linked to each other via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracene group.

In one or more embodiments, the compound represented by Formula 601 may be represented by Formula 601-1:

In Formula 601-1,

-   -   X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be         N or C(R₆₁₆), and at least one of X₆₁₄ to X₆₁₆ may be N,     -   L₆₁₁ to L₆₁₃ may each independently be the same as described in         connection with L₆₀₁,     -   xe611 to xe613 may each independently be the same as described         in connection with xe1,     -   R₆₁₁ to R₆₁₃ may each independently be the same as described in         connection with R₆₀₁, and     -   R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amidino group, a hydrazino group, a hydrazono         group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl         group, a biphenyl group, a terphenyl group, and a naphthyl         group.

In one embodiment, L₆₀₁ and L₆₁₁ to L₆₁₃ in Formulae 601 and 601-1 may each independently be selected from:

-   -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group; and     -   a phenylene group, a naphthylene group, a fluorenylene group, a         spiro-bifluorenylene group, a benzofluorenylene group, a         dibenzofluorenylene group, a phenanthrenylene group, an         anthracenylene group, a fluoranthenylene group, a         triphenylenylene group, a pyrenylene group, a chrysenylene         group, a perylenylene group, a pentaphenylene group, a         hexacenylene group, a pentacenylene group, a thiophenylene         group, a furanylene group, a carbazolylene group, an indolylene         group, an isoindolylene group, a benzofuranylene group, a         benzothiophenylene group, a dibenzofuranylene group, a         dibenzothiophenylene group, a benzocarbazolylene group, a         dibenzocarbazolylene group, a dibenzosilolylene group, a         pyridinylene group, an imidazolylene group, a pyrazolylene         group, a thiazolylene group, an isothiazolylene group, an         oxazolylene group, an isoxazolylene group, a thiadiazolylene         group, an oxadiazolylene group, a pyrazinylene group, a         pyrimidinylene group, a pyridazinylene group, a triazinylene         group, a quinolinylene group, an isoquinolinylene group, a         benzoquinolinylene group, a phthalazinylene group, a         naphthyridinylene group, a quinoxalinylene group, a         quinazolinylene group, a cinnolinylene group, a         phenanthridinylene group, an acridinylene group, a         phenanthrolinylene group, a phenazinylene group, a         benzimidazolylene group, an isobenzothiazolylene group, a         benzoxazolylene group, an isobenzoxazolylene group, a         triazolylene group, a tetrazolylene group, an         imidazopyridinylene group, an imidazopyrimidinylene group, and         an azacarbazolylene group, each substituted with at least one         selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a         cyano group, a nitro group, an amidino group, a hydrazino group,         a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group,         a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group,     -   but embodiments of the present disclosure are not limited         thereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

In one or more embodiments, R₆₀₁ and R₆₁₁ to R₆₁₃ in Formulae 601 and 601-1 may each independently be selected from:

-   -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group;     -   a phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group, each substituted with at least one selected         from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         phenyl group, a biphenyl group, a terphenyl group, a naphthyl         group, a fluorenyl group, a spiro-bifluorenyl group, a         benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl         group, an anthracenyl group, a fluoranthenyl group, a         triphenylenyl group, a pyrenyl group, a chrysenyl group, a         perylenyl group, a pentaphenyl group, a hexacenyl group, a         pentacenyl group, a thiophenyl group, a furanyl group, a         carbazolyl group, an indolyl group, an isoindolyl group, a         benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl         group, an imidazolyl group, a pyrazolyl group, a thiazolyl         group, an isothiazolyl group, an oxazolyl group, an isoxazolyl         group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl         group, a pyrimidinyl group, a pyridazinyl group, a triazinyl         group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl         group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl         group, a phenanthridinyl group, an acridinyl group, a         phenanthrolinyl group, a phenazinyl group, a benzimidazolyl         group, an isobenzothiazolyl group, a benzoxazolyl group, an         isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, and an         azacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂),

-   -   wherein Q₆₀₁ and Q₆₀₂ may each independently be the same as         described above.

The hole transport region 170 may include at least one compound selected from Compounds ET1 to ET37, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the electron transport region 170 may include at least one compound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), 2,4,6-tris(biphenyl-3-yl)-1,3,5-triazine (T2T), 2,4,6-tris(3-(pyrimidin-5-yl)phenyl)-1,3,5-triazine (TPM-TAZ), and NTAZ.

In one embodiment, the electron transport region 170 may include a phosphine oxide-containing compound, but embodiments of the present disclosure are not limited thereto. In one embodiment, the phosphine oxide-containing compound may be used in a hole blocking layer in the electron transport region 170, but embodiments of the present disclosure are not limited thereto.

The thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each independently be about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are within these ranges, excellent hole blocking characteristics and/or excellent electron control characteristics may be obtained without a substantial increase in driving voltage.

A thickness of the electron transport layer may be about 50 Å to about 1,000 Å, for example, from about 50 Å to about 500 Å. When the thickness of the electron transport layer is within the range, the electron transport layer may have satisfactory electron transport characteristics without a substantial increase in driving voltage.

The electron transport region 170 (for example, the electron transport layer in the electron transport region 170) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include at least one selected from an alkali metal complex and an alkaline earth-metal complex. The alkali metal complex may include a metal ion selected from a Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy diphenyloxadiazole, a hydroxy diphenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) or ET-D2:

The electron transport region 170 may include an electron injection layer to facilitate injection of electrons from the second electrode 190. The electron injection layer may be in direct contact with the second electrode 190.

The electron injection layer may have: i) a single-layered structure including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting of) a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including (e.g., consisting of) a plurality of different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In one embodiment, the alkali metal may be Li, Na, or Cs. In one or more embodiments, the alkali metal may be Li or Cs, but embodiments of the present disclosure are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from scandium (Sc), yttrium (Y), cerium (Ce), terbium (Tb), ytterbium (Yb), and gadolinium (Gd).

The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may be selected from oxides and halides (for example, fluorides, chlorides, bromides, and/or iodides) of the alkali metal, the alkaline earth-metal, and the rare earth metal, respectively.

The alkali metal compound may be selected from alkali metal oxides (such as Li₂O, Cs₂O, and/or K₂O), and alkali metal halides (such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI). In one embodiment, the alkali metal compound may be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal oxides (such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), and/or Ba_(x)Ca_(1-x)O (0<x<1)).

In one embodiment, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In one embodiment, the rare earth metal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃, but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may respectively include ions of an alkali metal, an alkaline earth-metal, and a rare earth metal as described above, and each ligand coordinated with the metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy diphenyloxadiazole, hydroxy diphenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

The electron injection layer may include (e.g., consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof, as described above. In one or more embodiments, the electron injection layer may further include an organic material. When the electron injection layer further includes an organic material, the alkali metal, alkaline earth metal, rare earth metal, alkali metal compound, alkaline earth-metal compound, rare earth metal compound, alkali metal complex, alkaline earth-metal complex, rare earth metal complex, or combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range, the electron injection layer may have satisfactory electron injection characteristics without a substantial increase in driving voltage.

Second Electrode 190

The second electrode 190 is located on the above-described organic layer. The second electrode 190 may be a cathode, which is an electron injection electrode, and in this regard, a material for forming the second electrode 190 may be selected from a metal, an alloy, an electrically conductive compound, and a combination thereof, each having a relatively low work function.

The second electrode 190 may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are not limited thereto. The second electrode 190 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure or a multi-layered structure including two or more layers.

The organic light-emitting device 10 may further include a capping layer positioned in a direction of light emission. The capping layer may increase the external luminescence efficiency of the device according to the principle of constructive interference.

The capping layer may be an organic capping layer including (e.g., consisting of) an organic material, an inorganic capping layer including (e.g., consisting of) an inorganic material, or a composite capping layer including an organic material and an inorganic material.

The capping layer may include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, and alkaline earth-metal complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may be optionally substituted with a substituent containing at least one element selected from O, N, S, Se, Si, F, Cl, Br, and I.

In one embodiment, the capping layer may include an amine-based compound.

In one or more embodiments, the capping layer may include a compound represented by Formula 201 or a compound represented by Formula 202.

In one or more embodiments, the capping layer may include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5 below, but embodiments of the present disclosure are not limited thereto:

Description of FIG. 2

FIG. 2 is a schematic view of a structure of an organic light-emitting device 20 according to another embodiment of the present disclosure.

Referring to FIG. 2 , the organic light-emitting device 20 according to another aspect of the present disclosure includes: a first electrode 110; a second electrode 190 facing the first electrode 110; m emission units ELU1, ELU(m−1), and ELU(m) between the first electrode 110 and the second electrode 190; and m−1 charge generating layers CGL(m−1) located between two adjacent emission units of the m emission units ELU1, ELU(m−1), and ELU(m), each of the charge generating layers CGL(m−1) including one n-type charge generating layer and one p-type charge generating layer, wherein m is an integer of 2 or more, the m emission units ELU1, ELU(m−1), and ELU(m) each include a hole transport region, an emission layer, and an electron transport region stacked in this order, a first hole transport region 130 of the m hole transport regions includes a hole injection layer 132 between the first electrode 110 and a first emission layer 150 and an auxiliary layer 131 between the first electrode 110 and the hole injection layer 132, the auxiliary layer 131 includes a fluoride of a metal having a work function of 3.8 eV or more, and the hole injection layer 132 includes a p-dopant.

For example, the hole transport region 130 may further include a hole transport layer 133 between the first electrode 110 and the hole injection layer 132.

The first electrode 110, the hole transport region 150, the auxiliary layer 131, the hole injection layer 132, the hole transport layer 133, the emission layer 150, the electron transport region, and the second electrode 190 may each independently be the same as described above.

Furthermore, the charge generating layer CGL(m−1) may be understood by referring to the descriptions of the hole transport region 130 (e.g., corresponding to the p-type charge generating layer) and the electron transport region 170 (e.g., corresponding to the n-type charge generating layer).

For example, the charge generating layer CGL(m−1) may include a same compound included in the hole transport region 130 and/or the electron transport region 170.

Hereinbefore, the organic light-emitting device 10 has been described in connection with FIGS. 1 to 2 . However, embodiments of the present disclosure are not limited thereto.

The layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region may be formed in a set or predetermined region using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec, depending on the material to be included and the structure of the layer to be formed.

When the layers constituting the hole transport region, the emission layer, and the layers constituting the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to 200° C., depending on the material to be included and the structure of the layer to be formed.

Apparatus

The organic light-emitting device as described above may be included in any suitable apparatus.

Another aspect of the present disclosure provides an apparatus including the organic light-emitting device.

For example, the apparatus may be a light-emitting apparatus, an authentication apparatus, or an electronic apparatus, but embodiments of the present disclosure are not limited thereto.

Light-Emitting Apparatus

In a light-emitting apparatus, a color filter may be located on or along at least one traveling direction of light emitted from the organic light-emitting device.

In one embodiment, the organic light-emitting device may include a first electrode, a first emission unit, a first charge generating unit, a second emission unit, and a second electrode. For example, the first emission unit and the second emission unit may each be to emit blue light, but embodiments of the present disclosure are not limited thereto.

A first substrate of the light-emitting apparatus may include a plurality of subpixel areas, and the color filter may include a plurality of color filter areas respectively corresponding to the plurality of subpixel areas. A pixel-defining film may be formed between the plurality of subpixel areas to define each of the subpixel areas. The color filter may include light blocking patterns between the plurality of color filter areas.

The plurality of color filter areas may include a first color filter area to emit first color light, a second color filter area to emit second color light, and a third color filter area to emit third color light, where the first color light, the second color light, and the third color light may have different maximum emission wavelengths from one another. For example, the first color light may be red light, the second color light may be green light, and the third color light may be blue light, but embodiments of the present disclosure are not limited thereto.

The first color filter area, the second color filter area, and the third color filter area may each further include a scatter, but embodiments of the present disclosure are not limited thereto.

In one embodiment, the organic light-emitting device may be to emit first light, the first color filter area may be to absorb the first light and emit first first-color light, the second color filter area may be to absorb the first light and emit second first-color light, and the third color filter area may be to absorb the first light and emit third first-color light. In this regard, the first first-color light, the second first-color light, and the third first-color light may have different maximum emission wavelengths from one another. For example, the first light may be blue light, the first first-color light may be red light, the second first-color light may be green light, and the third first-color light may be blue light, but embodiments of the present disclosure are not limited thereto.

The light-emitting apparatus may further include a thin-film transistor in addition to the organic light-emitting device as described above. The thin-film transistor may include a source electrode, a drain electrode, and an activation layer, wherein any one of the source electrode or the drain electrode may be electrically connected to any one of the first electrode or the second electrode of the organic light-emitting device (e.g., connected to either the first electrode or the second electrode).

The thin-film transistor may further include a gate electrode, a gate insulation layer, and/or the like.

The activation layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like, but embodiments of the present disclosure are not limited thereto.

The light-emitting apparatus may further include a sealing portion for sealing an organic light-emitting device. The sealing portion may be located between the color filter and the organic light-emitting device. The sealing portion may allow an image from the organic light-emitting device to be implemented and may block outside air and moisture from penetrating into the organic light-emitting device. The sealing portion may be a sealing substrate including a transparent glass or a plastic substrate. The sealing portion may be a thin film encapsulation layer including a plurality of organic layers and/or a plurality of inorganic layers. When the sealing portion is a thin-film encapsulation layer, the entire light-emitting apparatus may be flexible.

The light-emitting apparatus may be used as any suitable display, light source, and/or the like.

Authentication Apparatus

The authentication apparatus may be, for example, a biometric authentication apparatus for authenticating an individual using biometric information of a biometric body (for example, a fingertip, a pupil, and/or the like).

The authentication apparatus may further include, in addition to the organic light-emitting device, a biometric information collector.

Electronic Apparatus

The electronic apparatus may be applied to personal computers (for example, a mobile personal computer), mobile phones, digital cameras, electronic organizers, electronic dictionaries, electronic game machines, medical instruments (for example, electronic thermometers, sphygmomanometers, blood glucose meters, pulse measurement devices, pulse wave measurement devices, electrocardiogram (ECG) displays, ultrasonic diagnostic devices, or endoscope displays), fish finders, any suitable measuring instruments, meters (for example, meters for a vehicle, an aircraft, and a vessel), projectors, and/or the like, but embodiments of the present disclosure are not limited thereto.

General Definition of Substituents

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched aliphatic saturated hydrocarbon monovalent group having 1 to 60 carbon atoms, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having substantially the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkyl group, and non-limiting examples thereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group” as used herein refers to a divalent group having substantially the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is a C₁-C₆₀ alkyl group), and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms, and non-limiting examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having substantially the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group” used herein refers to a monovalent monocyclic group having 3 to 10 carbon atoms, at least one carbon-carbon double bond in the ring thereof, and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having substantially the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms, and at least one carbon-carbon double bond in its ring. Non-limiting examples of the C₁-C₁₀ heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group” as used herein refers to a divalent group having substantially the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the term “C₆-C₆₀ arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each include two or more rings, the two or more rings may be fused to each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include two or more rings, the two or more rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to —OA₁₀₂ (wherein A₁₀₂ is a C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group” as used herein refers to —SA₁₀₃ (wherein A₁₀₃ is a C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed with each other, only carbon atoms as ring-forming atoms, and non-aromaticity in its entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed polycyclic group is a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group having two or more rings condensed with each other, at least one heteroatom selected from N, O, Si, P, and S in addition to carbon atoms (for example, 1 to 60 carbon atoms), as ring-forming atoms, and non-aromaticity in its entire molecular structure. A non-limiting example of the monovalent non-aromatic condensed heteropolycyclic group is a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having substantially the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₄-C₆₀ carbocyclic group” as used herein refers to a monocyclic or polycyclic group having 4 to 60 carbon atoms, in which the ring-forming atoms are carbon atoms only. The term “C₄-C₆₀ carbocyclic group” as used herein refers to an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C₄-C₆₀ carbocyclic group may be a ring (such as benzene), a monovalent group (such as a phenyl group), or a divalent group (such as a phenylene group). In one or more embodiments, depending on the number of substituents connected to the C₄-C₆₀ carbocyclic group, the C₄-C₆₀ carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₂-C₆₀ heterocyclic group” as used herein refers to a group having substantially the same structure as the C₄-C₆₀ carbocyclic group, except that at least one heteroatom selected from N, O, Si, P, and S is used in addition to carbon (for example, 2 to 60 carbon atoms) as a ring-forming atom.

In the present specification, at least one substituent of the substituted C₄-C₆₀ carbocyclic group, the substituted C₂-C₆₀ heterocyclic group, the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

-   -   deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amidino group, a hydrazino group, a         hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a         C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, and a C₁-C₆₀ alkoxy group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy         group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a         monovalent non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group,         —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),         —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, and a monovalent non-aromatic         condensed heteropolycyclic group;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, and a monovalent non-aromatic         condensed heteropolycyclic group, each substituted with at least         one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amidino group, a hydrazino         group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl         group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀         cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀         cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀         aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a         C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed         polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),         —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂);         and     -   —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),         —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),     -   wherein Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each         independently be selected from hydrogen, deuterium, —F, —Cl,         —Br, —I, a hydroxyl group, a cyano group, a nitro group, an         amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀         alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a         C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀         heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀         heteroaryl group, a monovalent non-aromatic condensed polycyclic         group, a monovalent non-aromatic condensed heteropolycyclic         group, a C₁-C₆₀ alkyl group substituted with at least one         selected from deuterium, —F, and a cyano group, a C₆-C₆₀ aryl         group substituted with at least one selected from deuterium, —F,         and a cyano group, a biphenyl group, and a terphenyl group.

The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the term “ter-Bu” or “Bu^(t)” as used herein refers to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group”. In other words, the “biphenyl group” is a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group”. In other words, the “terphenyl group” is a substituted phenyl group having, as a substituent, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group.

*, *′, and *″, as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, an organic light-emitting device according to embodiments of the present disclosure will be described in more detail with reference to Examples.

EXAMPLES Example 1

As an anode, a 15 Ω/cm² (1,200 Å) ITO/Ag/ITO glass substrate from Corning, Inc. was cut to a size of 50 mm×50 mm×0.7 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then cleaned by irradiation of ultraviolet rays and exposure to ozone for 30 minutes. Then, the glass substrate was loaded onto a vacuum deposition apparatus.

AlF₃ was vacuum-deposited on the glass substrate to form an auxiliary layer having a thickness of 15 Å, HT45 and F₄-TCNQ were co-deposited at a volume ratio of 90:10 thereon to form a hole injection layer having a thickness of 50 Å, and then HT45 was vacuum-deposited thereon to form a first hole transport layer having a thickness of 165 Å.

TCTA was deposited on the first hole transport layer to form a second hole transport layer having a thickness of 50 Å, and H18 (host) and FD23 (dopant) were co-deposited at a volume ratio of 100:3 on the second hole transport layer to form an emission layer having a thickness of 170 Å.

T2T was deposited on the emission layer to form a first electron transport layer having a thickness of 50 Å, and TPM-TAZ and LiQ were co-deposited at a volume ratio of 1:1 on the first electron transport layer to form a second electron transport layer having a thickness of 250 Å, thereby completing the formation of a first emission unit.

ET37 and Li were co-deposited at a volume ratio of 99:1 on the first emission unit to form an n-type charge generating layer having a thickness of 100 Å, and HT45 and F₄-TCNQ were co-deposited at a volume ratio of 90:10 thereon to form a p-type charge generating layer having a thickness of 100 Å, thereby completing the formation of a first charge generating unit.

HT45 was deposited on the first charge generating unit to form a first hole transport layer having a thickness of 530 Å, TCTA was deposited on the first hole transport layer to form a second hole transport layer having a thickness of 50 Å, H18 and FD23 were co-deposited at a volume ratio of 100:3 on the second hole transport layer to form an emission layer having a thickness of 170 Å, T2T was deposited on the emission layer to form a first electron transport layer having a thickness of 50 Å, and TPM-TAZ and LiQ were co-deposited at a volume ratio of 1:1 on the first electron transport layer to form a second electron transport layer having a thickness of 250 Å, thereby completing the formation of a second emission unit.

ET37 and Li were co-deposited at a volume ratio of 99:1 on the second emission unit to form an n-type charge generating layer having a thickness of 100 Å, and HT45 and F4-TCNQ were co-deposited at a volume ratio of 90:10 thereon to form a p-type charge generating layer having a thickness of 100 Å, thereby completing the formation of a second charge generating unit.

HT45 was deposited on the second charge generating unit to form a first hole transport layer having a thickness of 470 Å, TCTA was deposited on the first hole transport layer to form a second hole transport layer having a thickness of 50 Å, H18 and FD23 were co-deposited at a volume ratio of 100:3 on the second hole transport layer to form an emission layer having a thickness of 170 Å, T2T was deposited on the emission layer to form a first electron transport layer having a thickness of 50 Å, and TPM-TAZ and LiQ were co-deposited at a volume ratio of 1:1 on the first electron transport layer to form a second electron transport layer having a thickness of 350 Å, thereby completing the formation of a third emission unit.

KI and Yb were co-deposited at a volume ratio of 90:10 on the third emission unit to form an electron injection layer having a thickness of 11 Å.

Ag and Mg were co-deposited at a volume ratio of 9:1 on the electron injection layer to form a cathode having a thickness of 140 Å, thereby completing the manufacture of a tandem organic light-emitting device.

Example 2

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that HT45 and AlF₃ were co-deposited at a volume ratio of 100:30 to form an auxiliary layer having a thickness of 15 Å instead of the AlF₃ auxiliary layer.

Example 3

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that in Example 1, the n-type charge generating layer was formed to have a thickness of 50 Å, the first hole transport layer of the second emission unit was formed to have a thickness of 580 Å, and the first hole transport layer of the third emission unit was formed to have a thickness of 520 Å.

Example 4

An organic light-emitting device was manufactured in substantially the same manner as in Example 3, except that in the first emission unit of Example 3, the hole injection layer is not included between the AlF₃ auxiliary layer and the hole transport layer, and HT45 was vacuum-deposited to form a first hole transport layer having a thickness of 215 Å.

Comparative Example 1

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that the AlF₃ auxiliary layer was not included between the anode and the hole injection layer, and HT45 was vacuum-deposited to form a first hole transport layer having a thickness of 178 Å of a first emission unit.

Comparative Example 2

An organic light-emitting device was manufactured in substantially the same manner as in Example 3, except that in Example 3, the AlF₃ auxiliary layer was not included between the anode and the hole injection layer, and HT45 was vacuum-deposited to form a first hole transport layer having a thickness of 178 Å of a first emission unit.

Comparative Example 3

An organic light-emitting device was manufactured in substantially the same manner as in Example 3, except that the AlF₃ auxiliary layer and the hole injection layer were not included between the anode and the first hole transport layer, and HT45 was vacuum-deposited to form a first hole transport layer having a thickness of 228 Å of a first emission unit.

Comparative Example 4

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that Compound A and AlF₃ were co-deposited at a weight ratio of 95:5 on the glass substrate to form an auxiliary layer, a hole injection layer was not formed, and a hole transport layer was directly deposited on the auxiliary layer.

Comparative Example 5

An organic light-emitting device was manufactured in substantially the same manner as in Example 1, except that on the anode, without forming an auxiliary layer, Compound B and Compound C were co-deposited at a weight ratio of 3:97 to form a hole injection layer on the anode, without forming an auxiliary layer.

Evaluation Example 1

The driving voltage, change in driving voltage, current efficiency, lifespan, and CIE color coordinate of the organic light-emitting devices manufactured according to Examples 1 and 2 and Comparative Example 1 were measured using a Keithley SMU 236 and a luminance meter PR650, and the results are shown in Table 1. The lifespan (T97) is a period of time taken until the luminance (@1,464 nit) was reduced to 97% of initial luminance (100%) after an organic light-emitting device was driven.

TABLE 1 First emission unit Thickness of n-type Hole charge Driving Current Lifespan Color Auxiliary injection generating voltage efficiency (T₉₇) coordinate layer layer layer (V) (cd/A) (hr) (y) Example 1 AlF₃ O 100 Å 10.7 38.8 433 0.136 Example 2 HT45:AlF₃ O 10.8 37.1 461 0.144 (100:30)  Comparative (none) O 11.1 35.9 427 0.138 Example 1

Referring to Table 1, it is confirmed that the organic light-emitting devices manufactured according to Examples 1 and 2 have reduced driving voltages and improved efficiencies, compared to the organic light-emitting device manufactured according to Comparative Example 1, and the organic light-emitting devices manufactured according to Examples 1 and 2 and Comparative Example 1 are on the same level in terms of lifespan.

Evaluation Example 2

The driving voltage, change in driving voltage, current efficiency, lifespan, and CIE color coordinate of the organic light-emitting devices manufactured according to Examples 3 and 4 and Comparative Examples 2 and 3 were measured using a Keithley SMU 236 and a luminance meter PR650, and the results are shown in Table 2. The lifespan (T₉₇) is a period of time taken until the luminance (@1,464 nit) was reduced to 97% of initial luminance (100%) after an organic light-emitting device was driven.

TABLE 2 First emission unit Thickness of n-type Hole charge Driving Current Lifespan Color Auxiliary injection generating voltage efficiency (T₉₇) coordinate layer layer layer (V) (cd/A) (hr) (y) Example 3 AlF₃ O 50 Å 12.3 36.3 291 0.090 Example 4 AlF₃ (none) 12.2 37.0 283 0.090 Comparative (none) O 12.6 35.7 282 0.088 Example 2 Comparative (none) (none) 13.1 35.8 8 0.087 Example 3

Referring to Table 2, it is confirmed that the organic light-emitting devices manufactured according to Examples 3 and 4 have reduced driving voltage and improved efficiency, compared to the organic light-emitting device manufactured according to Comparative Example 2, and the organic light-emitting devices manufactured according to Examples 3 and 4 and Comparative Example 2 are on the same level in terms of lifespan. For example, it is confirmed that the organic light-emitting device manufactured according to Example 4 has similar characteristics as the organic light-emitting device manufactured according to Example 3 despite absence of a hole injection layer. In contrast, it is confirmed that an organic light-emitting device that does not have an auxiliary layer such as the organic light-emitting devices manufactured according to Comparative Examples 2 and 3 has increased driving voltage and reduced lifespan.

According to embodiments of the present disclosure, when a fluoride of a metal included in the auxiliary layer has a high dielectric constant, an energy barrier between a first electrode and a hole injection layer may be mitigated or decreased through band bending, a work function may be lowered through electron transfer between materials included in the hole injection layer adjacent to the auxiliary layer, and hole injection characteristics may be improved.

As used herein, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art.

Any numerical range recited herein is intended to include all sub-ranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

It should be understood that the embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as being available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims and equivalents thereof. 

What is claimed is:
 1. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an organic layer comprising: an emission layer between the first electrode and the second electrode; and a hole transport region between the first electrode and the emission layer, wherein the hole transport region comprises: a hole injection layer and/or a hole transport layer located between the first electrode and the emission layer; and an auxiliary layer between the first electrode and one of the hole injection layer or the hole transport layer, the auxiliary layer comprises a fluoride of a metal, the metal being at least one selected from gallium (Ga), indium (In), and thallium (Tl), and the one of the hole injection layer or the hole transport layer comprises a p-dopant.
 2. The organic light-emitting device of claim 1, wherein the auxiliary layer comprises at least one selected from GaF₃, InF₃, and TlF₃.
 3. The organic light-emitting device of claim 1, wherein the auxiliary layer consists of a single film of the fluoride of the metal, or further comprises a hole transport material.
 4. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an organic layer comprising: an emission layer between the first electrode and the second electrode; and a hole transport region between the first electrode and the emission layer, wherein the hole transport region comprises: a hole injection layer and/or a hole transport layer located between the first electrode and the emission layer; and an auxiliary layer between the first electrode and one of the hole injection layer or the hole transport layer, the auxiliary layer comprises a fluoride of a Group III metal, the one of the hole injection layer or the hole transport layer comprises a p-dopant, wherein the auxiliary layer further comprises a hole transport material, and a volume ratio between the fluoride of the metal and the hole transport material is 100:x, where x is greater than 0 and less than
 100. 5. The organic light-emitting device of claim 4, wherein the hole transport material is at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB, β-NPB, TPD, spiro-TPD, spiro-NPB, α-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzene sulfonic acid (PANI/DBSA), poly(3,4-ethylene dioxythiophene)/poly(4-styrene sultanate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrene sultanate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

wherein, in Formulae 201 and 202, L₂₀₁ to L₂₀₅ are each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group, xa1 to xa4 are each independently selected from 0, 1, 2, and 3, xa5 is selected from 1, 2, 3, 4, and 5, and R₂₀₁ to R₂₀₄ are each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.
 6. The organic light-emitting device of claim 1, wherein the auxiliary layer directly contacts the first electrode.
 7. The organic light-emitting device of claim 1, wherein the auxiliary layer directly contacts the one of the hole injection layer or the hole transport layer.
 8. The organic light-emitting device of claim 1, wherein the auxiliary layer has a thickness of about 5 Å to about 200 Å.
 9. The organic light-emitting device of claim 1, wherein the p-dopant has a lowest unoccupied molecular orbital (LUMO) energy level of less than about −3.5 eV.
 10. The organic light-emitting device of claim 1, wherein the p-dopant comprises at least one selected from quinone derivatives, metal oxides, cyano group-containing compounds, and alkyl halides.
 11. The organic light-emitting device of claim 1, wherein the p-dopant is generated according to Reaction Scheme 1 at an interface between the auxiliary layer and the one of the hole injection layer or the hole transport layer, and comprises a compound represented by metal M and M′F₃:

wherein, in Reaction Scheme 1, M is a Group III metal, M′ is a metal element included in the metal oxide comprised in the one of the hole injection layer or the hole transport layer, and a satisfies 0<α<5.
 12. The organic light-emitting device of claim 1, wherein the one of the hole injection layer or the hole transport layer further comprises a material including an electron withdrawing group (EWG).
 13. The organic light-emitting device of claim 1, wherein the hole transport region comprises: the hole injection layer; and the hole transport layer between the hole injection layer and the emission layer, the hole injection layer comprises a p-dopant, and the hole transport layer comprises a hole transport material.
 14. The organic light-emitting device of claim 13, wherein the hole transport region further comprises an electron blocking layer between the hole transport layer and the emission layer.
 15. The organic light-emitting device of claim 1, wherein an electron transport region is further located between the emission layer and the second electrode, and the electron transport region comprises an electron transport material.
 16. The organic light-emitting device of claim 15, wherein the electron transport region comprises at least one layer selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer.
 17. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; m emission units between the first electrode and the second electrode; and m−1 charge generating layers between two adjacent emission units of them emission units, each of the m−1 charge generating layers comprising one n-type charge generating layer and one p-type charge generating layer, wherein m is an integer of 2 or more, the m emission units each comprise a hole transport region, an emission unit, and an electron transport region, arranged in order, a first hole transport region of the m hole transport regions comprises: a hole injection layer and/or a hole transport layer located between the first electrode and a first emission layer; and an auxiliary layer between the first electrode and one of the hole injection layer or the hole transport layer, the auxiliary layer comprises a fluoride of a metal, the metal being at least one selected from gallium (Ga), indium (In), and thallium (Tl), and the one of the hole injection layer or the hole transport layer comprises a p-dopant.
 18. A display apparatus comprising: a thin-film transistor comprising a source electrode, a drain electrode, and an activation layer; and the organic light-emitting device of claim 1, wherein the first electrode of the organic light-emitting device is in electrical connection with one selected from the source electrode and the drain electrode of the thin-film transistor. 